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BACKGROUND Compartment syndrome of the forearm has been associated with a variety of etiologies, including fractures, snake bites, complications of certain infections, and, very rarely, spider bites. Loxoscelism is the venom-related clinical manifestation of the bite of spiders of the genus Loxosceles, also called brown or fiddler (violinist) spiders. It manifests locally/regionally with pain, erythema, and edema, with subsequent necrotic plaque formation at the site of the bite. This condition can threaten the function and integrity of the limbs and, in severe cases, can be life-threatening. The basis of treatment is surgical decompression of the affected compartments to restore limb perfusion and avoid irreversible sequelae. CASE REPORT A 62-year-old male patient, without comorbidities, had edematous cutaneous loxoscelism and secondary development of acute compartment syndrome of the right forearm. He promptly visited the Emergency Department and underwent surgical treatment, in addition to the application of pharmacological treatment, under a multidisciplinary team. The evolution was favorable. The biochemical levels of rhabdomyolysis decreased, the compartment syndrome resolved, the fasciotomies were closed, and the patient was discharged without further complications. CONCLUSIONS Although arachnid bites are relatively uncommon in urban hospitals, it is crucial that general, vascular, and plastic surgeons maintain a high index of clinical suspicion for acute compartment syndrome. It is important to make an accurate differential diagnosis, and equally important is the interdisciplinary approach to treating this condition, ensuring prompt medical treatment and, if necessary, early surgical intervention.

Background: Spiders of the genus Loxosceles are distributed throughout tropical and temperate regions worldwide. Loxosceles spp. bites may evolve to necrosis, with or without intravascular hemolysis. There is no consensus regarding the best treatment to prevent necrosis. The objective of this study was to evaluate the factors associated with the development of necrosis and the impact that antivenom administration has on the evolution of cutaneous loxoscelism., Methodology/principal Findings: This was a prospective observational study carried out at a referral center for envenoming. Over a 6-year period, we included 146 patients with a presumptive or definitive diagnosis of loxoscelism. Depending on the symptom severity, a polyvalent anti-arachnid antivenom was administered or not-in 74 cases (50.7%) and 72 cases (49.3%), respectively. Cutaneous and systemic manifestations were assessed at admission and weekly thereafter. Adverse reactions to the antivenom were also evaluated. Cutaneous loxoscelism was observed in 141 cases (96.6%), and the spider was identified in 29 (19.9%). The mean time from bite to antivenom administration was 41.6 ± 27.4 h. After discharge, 130 patients (90.9%) were treated with corticosteroids, antihistamines and analgesics being prescribed as needed. The probability of developing necrosis was significantly lower among the patients who were admitted earlier, as well as among those who received antivenom (p = 0.0245). Among the 74 patients receiving antivenom, early and delayed adverse reactions occurred in seven (9.5%) and four (5.4%), respectively. Local infection was observed only in three (2.3%) of the 128 patients for whom that information was available., Conclusions/significance: Necrosis after a Loxosceles sp. bite appears to more common when hospital admission is delayed or when antivenom is not administered. In addition, the administration of a polyvalent anti-arachnid antivenom appears to be safe, with a relatively low rate of adverse reactions., Competing Interests: The authors have declared that no competing interests exist.

Background: Rhabdomyolysis after spider bite has been reported in a small number of patients, and myocarditis in even fewer. However, arrhythmia associated with latrodectism in children has not been described in the literature to date., Case Summary: A girl presented approximately 4.5 h after being bitten on the left ankle by a black spider. Two unifocal premature ventricular contractions (PVCs) were observed on the electrocardiogram. In laboratory tests, creatine kinase was elevated. On day 2, levels of troponin, pro-brain and natriuretic peptide were elevated. Electrocardiogram revealed inverted and biphasic T waves. Echocardiography revealed mild left ventricular dilation, mitral and aortic valve regurgitation. Holter electrocardiogram showed PVCs. Her laboratory and echocardiography findings completely normalized after discharge, and no arrhythmia was observed on the Holter electrocardiogram during outpatient follow-up., Conclusion: Although spider bites are uncommon, they can cause serious systemic effects. These patients should be evaluated for arrhythmia, rhabdomyolysis and myocarditis., (© The Author(s) [2022]. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Inhibitor cystine knot (ICK) peptides are knotted peptides with three intramolecular disulfide bonds that affect several types of ion channels. Some are proteolytically stable and are promising scaffolds for drug development. GTx1-15 is an ICK peptide that inhibits the voltage-dependent calcium channel Ca v 3.1 and the voltage-dependent sodium channels Na v 1.3 and Na v 1.7. As a model molecule to develop an ICK peptide drug, we investigated several important pharmaceutical characteristics of GTx1-15. The stability of GTx1-15 in rat and human blood plasma was examined, and no GTx1-15 degradation was observed in either rat or human blood plasma for 24 h in vitro. GTx1-15 in blood circulation was detected for several hours after intravenous and intramuscular administration, indicating high stability in plasma. The thermal stability of GTx1-15 as examined by high thermal incubation and protein thermal shift assays indicated that GTx1-15 possesses high heat stability. The cytotoxicity and immunogenicity of GTx1-15 were examined using the human monocytic leukemia cell line THP-1. GTx1-15 showed no cytotoxicity or immunogenicity even at high concentrations. These results indicate that GTx1-15 itself is suitable for peptide drug development and as a peptide library scaffold.

The clinical manifestations of a recluse spider bite range from local erythema to necrotic skin reactions; bites rarely lead to a systemic disease known as viscerocutaneous loxoscelism. A 29-y-old female patient was admitted to the emergency department with a wound, swelling, and pain on her left leg and a rash on her whole body as a result of a spider bite. On physical examination, a round, hard, black, irregularly shaped necrotic area was found in the bite zone on the lower posterior part of the left thigh, as were lesions in the form of erythematous papules around the area. There was a color change around the lesion, extending from posterior to medial of the thigh, and a papule on a diffuse erythematous surface on the trunk and arms. At follow-up, the necrotic area had become more apparent. After approximately 1 mo, the necrotic area was surgically debrided and a flap was formed on the necrotic tissue area. In this article, a case that was thought to be caused by a Loxosceles spider bite and which started with erythema, progressed to lymphangitis, cellulitis, and severe necrosis, and was surgically debrided, was evaluated in light of the clinical findings and previously reported cases of verified loxoscelism. In patients with a history suggestive of a bite and with these clinical findings, the diagnosis of a bite by Loxosceles spp. should be carefully considered based on clinical and epidemiologic findings., (Copyright © 2021 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.)

The sodium channels Na v 1.7, Na v 1.8 and Na v 1.9 are critical for pain perception in peripheral nociceptors. Loss of function of Na v 1.7 leads to congenital insensitivity to pain in humans. Here we show that the spider peptide toxin called HpTx1, first identified as an inhibitor of K v 4.2, restores nociception in Na v 1.7 knockout (Na v 1.7-KO) mice by enhancing the excitability of dorsal root ganglion neurons. HpTx1 inhibits Na v 1.7 and activates Na v 1.9 but does not affect Na v 1.8. This toxin produces pain in wild-type (WT) and Na v 1.7-KO mice, and attenuates nociception in Na v 1.9-KO mice, but has no effect in Na v 1.8-KO mice. These data indicate that HpTx1-induced hypersensitivity is mediated by Na v 1.9 activation and offers pharmacological insight into the relationship of the three Na v channels in pain signalling.

Envenoming due to Loxosceles spider bites still remains a neglected disease of particular medical concern in the Americas. To date, there is no consensus for the treatment of envenomed patients, yet horse polyclonal antivenoms are usually infused to patients with identified severe medical conditions. It is widely known that venom proteins in the 30-35 kDa range with sphingomyelinase D (SMasesD) activity, reproduce most of the toxic effects observed in loxoscelism. Hence, we believe that monoclonal antibody fragments targeting such toxins might pose an alternative safe and effective treatment. In the present study, starting from the monoclonal antibody LimAb7, previously shown to target SMasesD from the venom of L. intermedia and neutralize its dermonecrotic activity, we designed humanized antibody V-domains, then produced and purified as recombinant single-chain antibody fragments (scFvs). These molecules were characterized in terms of humanness, structural stability, antigen-binding activity, and venom-neutralizing potential. Throughout this process, we identified some blocking points that can impact the Abs antigen-binding activity and neutralizing capacity. In silico analysis of the antigen/antibody amino acid interactions also contributed to a better understanding of the antibody's neutralization mechanism and led to reformatting the humanized antibody fragment which, ultimately, recovered the functional characteristics for efficient in vitro venom neutralization.

Background: Black widow spider (Latrodectus spp) envenomation represents the most medically significant spider envenomation in the United States, prompting more than 2500 calls to poison centers annually. The female spider, which is responsible for symptomatic envenomations, is classically described as a shiny black spider with a red hourglass-shaped marking on the ventral abdomen. Clinical features of envenomation include painful muscle cramping, abdominal pain, and autonomic disturbances, such as tachycardia, hypertension, and diaphoresis. "Latrodectus facies" or "facies latrodectismica" is an additional distinctive but rarely described clinical finding characterized by periorbital edema, lacrimation, and blepharospasm., Case Report: A 6-year-old female developed the typical clinical features of Latrodectus envenomation after being found in bed with a Western black widow spider (Latrodectus hesperus) with no ventral marking. She initially improved with opioid analgesia, but 6 h later her symptoms worsened again, and concurrent with this worsening she developed Latrodectus facies. She received additional opioid analgesia and all her symptoms resolved within 24 h. Her mother provided informed and written consent for the acquisition and publication of the facial photographs presented. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: A high degree of clinical suspicion is necessary to correctly diagnose Latrodectus envenomation, especially when the spider escapes unnoticed or in young children in whom the bite is not witnessed. To our knowledge, Latrodectus facies has not been reported previously in a young child, and recognition of this finding will aid clinicians in limiting unnecessary interventions and administering appropriate therapy., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Loxoscelism is a common pathology in our environment with a broad spectrum of differential diagnoses and presentations, with potentially serious complications, even to the point of death. To date, there is no standard treatment for these patients., Aim: To describe the clinical manifestations, main complications, therapeutic management, and evolution of loxoscelism in an inpatient setting from a tertiary hospital in Chile., Methods: All patients consulting and hospitalized in the hospital of the Pontificia Universidad Católica de Chile with diagnosis of loxoscelism between 2014 to 2017 and evaluated by dermatologist were included. Review of clinical files, including symptoms, images, laboratory parameters and treatment., Results: We evaluated seventeen inpatient with loxoscelism, whose presentation responds to the national epidemiological pattern. Most cases were managed with antibiotics, systemic corticosteroids, antihistamines, and dapsone. From these, 11.8% corresponded to viscerocutaneous loxoscelism, successfully managed with supportive measures, systemic corticosteroids and antihistamines. Fifty-nine percent healed their cutaneous lesions after one month of treatment, with slight residual scarring or post inflammatory hyperpigmentation, without associated mortality in our series., Discussion: Most cases of cutaneous loxoscelism presented excellent response and rapid resolution of the disease after combined therapy with systemic corticosteroids, antibiotics and dapsone, suggesting that the use of these therapies could stop the progression of cutaneous necrosis and prevent complications associated with loxoscelism.

In Central Europe, reports of human envenomation by Cheiracanthium punctorium, commonly known as the yellow sac spider, are sporadic, despite the fact that this species is widespread in Europe. However, in recent years, C. punctorium has been repeatedly described globally in medical and toxicological literature. Its venom was found to possess insecticidal, haemolytic, cytotoxic, and membrane-damaging activities. Its bite is often very painful, frequently associated with local and transient cutaneous and neurotoxic effects, but sometimes also with systemic symptoms which require medical help. The main objective of this article is to introduce more details about C. punctorium, the clinical manifestations and circumstances of its bite, the characteristics of its venom and proposed clinical management. The authors provide case reports of patients bitten by C. punctorium during the 10-year observational period. All patients presented in this article showed generally mild clinical manifestations and recovered completely without sequelae. No further treatment in terms of hospital surveillance or specific clinical measures was necessary in any of the reported cases.

The venom of the Brazilian armed spider Phoneutria nigriventer is a rich source of biologically active peptides that have potential as analgesic drugs. In this study, we investigated the analgesic and adverse effects of peptide 3-5 (Tx3-5), purified from P. nigriventer venom, in several mouse models of pain. Tx3-5 was administered by intrathecal injection to mice selected as models of postoperative (plantar incision), neuropathic (partial sciatic nerve ligation) and cancer-related pain (inoculation with melanoma cells) in animals that were either sensitive or tolerant to morphine. Intrathecal administration of Tx3-5 (3-300 fmol/site) in mice could either prevent or reverse postoperative nociception, with a 50 % inhibitory dose (ID50) of 16.6 (3.2-87.2) fmol/site and a maximum inhibition of 87 ± 10 % at a dose of 30 fmol/site. Its effect was prevented by the selective activator of L-type calcium channel Bay-K8644 (10 μg/site). Tx3-5 (30 fmol/site) also produced a partial antinociceptive effect in a neuropathic pain model (inhibition of 67 ± 10 %). Additionally, treatment with Tx3-5 (30 fmol/site) nearly abolished cancer-related nociception with similar efficacy in both morphine-sensitive and morphine-tolerant mice (96 ± 7 and 100 % inhibition, respectively). Notably, Tx3-5 did not produce visible adverse effects at doses that produced antinociception and presented a TD50 of 1125 (893-1418) fmol/site. Finally, Tx3-5 did not alter the normal mechanical or thermal sensitivity of the animals or cause immunogenicity. Our results suggest that Tx3-5 is a strong drug candidate for the treatment of painful conditions.

Systemic lupus erythematosus is a chronic autoimmune disease with a relapsing and remitting course characterized by disease flares. Flares are a major cause of hospitalization, morbidity and mortality in patients with systemic lupus erythematosus. Some triggers for these exacerbations have been identified, including infections, vaccines, pregnancy, environmental factors such as weather, stress and drugs. We report a patient who presented with a lupus flare with predominantly mucocutaneous, serosal and cardiac involvement after being bitten by a spider and we present the possible mechanisms by which the venom elicited such a reaction. To the best of our knowledge, this is the first such case reported in the literature., (Copyright © 2015 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.)

Venom-derived peptides constitute a unique source of drug prototypes for the pain management. Many of them can modulate voltage-gated calcium channels that are central in the processing of pain sensation. PhTx3-4 is a peptide isolated from Phoneutria nigriventer venom, which blocks high voltage-activated calcium channels with low specificity, thereby leading to neuroprotection in models of ischemia in vitro. The aim of the present work was evaluating the potential of intrathecal PhTx3-4 in the reversal of different nociceptive states in mice, furthermore assessing the potential of PhTx3-4 in triggering motor side effects. We found that bellow 100 pmol/site, PhTx3-4 did not cause major motor side effects. By comparison, ω-conotoxin MVIIA and ω-conotoxin MVIIC triggered motor side effects at the doses of 10 and 100 pmol/site, respectively. Also, PhTx3-4 (30 pmol/site) caused no significant alterations in the forced locomotor activity test (rotarod) and in the exploratory activity test (versamax). In a model of inflammatory persistent pain (formalin test), PhTx3-4 reversed nociceptive behavior both pre or post-administered, although this effect was observed only at the inflammatory phase of the test and not at the neurogenic phase. Comparatively, ω-conotoxin MVIIC was effective only when post-administered in the formalin test. Nonetheless, PhTx3-4 treatment was devoid of action in acute nociceptive thermal model (hotplate test), whereas morphine showed efficacy in this test. Efficacy of PhTx3-4 in the formalin test was associated with inhibition of formalin-induced glutamate release in the cerebrospinal fluid. PhTx3-4, but not ω-conotoxin MVIIC, reversed NMDA-induced nociceptive behavior indicating a putative role of PhTx3-4 at ionotropic glutamate receptors. Finally, we observed efficacy of PhTx3-4 in ameliorating mechanical hypersensitivity induced by paw incision, a post-operative and more clinically relevant pain model. Taken together, our data show that PhTx3-4 possesses antinociceptive effect in different models of pain in mice, suggesting that this toxin may serve as drug prototype for pain control., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

N-type calcium channels play important roles in the control of neurotransmission release and transmission of pain signals to the central nervous system. Their selective inhibitors are believed to be potential drugs for treating chronic pain. In this study, a novel neurotoxin named Huwentoxin-XVI (HWTX-XVI) specific for N-type calcium channels was purified and characterized from the venom of Chinese tarantula Ornithoctonus huwena. HWTX-XVI is composed of 39 amino acid residues including six cysteines that constitute three disulfide bridges. HWTX-XVI could almost completely block the twitch response of rat vas deferens to low-frequency electrical stimulation. Electrophysiological assay indicated that HWTX-XVI specifically inhibited N-type calcium channels in rat dorsal root ganglion cells (IC50 ∼60 nM). The inhibitory effect of HWTX-XVI on N-type calcium channel currents was dose-dependent and similar to that of CTx-GVIA and CTx-MVIIA. However, the three peptides exhibited markedly different degrees of reversibility after block. The toxin had no effect on voltage-gated T-type calcium channels, potassium channels or sodium channels. Intraperitoneal injection of the toxin HWTX-XVI to rats elicited significant analgesic responses to formalin-induced inflammation pain. Toxin treatment also changed withdrawal latency in hot plate tests. Intriguingly, we found that intramuscular injection of the toxin reduced mechanical allodynia induced by incisional injury in Von Frey test. Thus, our findings suggest that the analgesic potency of HWTX-XVI and its greater reversibility could contribute to the design of a novel potential analgesic agent with high potency and low side effects., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Loxosceles Spiders have a worldwide distribution and are considered one of the most medically important groups of Spiders. The venom from Spiders of the genus Loxosceles, the most famous being Loxosceles reclusa (brown recluse Spider), can promote severe local and systemic damages. This report describes a girl presenting with a Spider bite over her right upper eyelid.

Horner's syndrome involves a triad of eyelid ptosis, miosis, and facial anhidrosis that results from disruption of the oculosympathetic pathway. Acquired Horner's syndrome is associated with a variety of medical conditions including Pancoast tumor and carotid dissection. We report the unique case of a 47-year-old man presenting with Horner's syndrome 4 weeks after black widow spider envenomation. Workup did not reveal any alternative explanatory etiology. We hypothesize that late sequelae of black widow spider envenomation secondary to autonomic nerve injury or retrograde axonal transport after mechanical inoculation may have led to an acquired defect in the oculosympathetic pathway resulting in a Horner's syndrome. This case introduces a rare cause of Horner's syndrome and highlights the importance of environmental exposures in the evaluation of these patients., (Copyright © 2012 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.)

Brown recluse spiders are predominantly found in south central United States. Their bites usually cause mild self-limiting reactions, although localized tissue necrosis and rare systemic, potentially fatal, envenomations are known to occur. Herein, we report an atypical presentation of a brown recluse bite in a 20 year old female who was admitted to the intensive care unit due to angioedema and cellulitis. We photographically document the bite site for twenty-four hours following envenomation. She received glucocorticoids, antihistamines, antibiotics and dapsone while hospitalized and was subsequently discharged with complete resolution of symptoms without the development of tissue necrosis or scarring.

Although wolf spider venom has been implicated in necrotic arachnidism without acceptably documented verification, limited, prospectively collected data demonstrate a lack of cutaneous necrosis. The infrequent nature of exposure and inherent difficulty in confirming wolf spider bites in humans makes it challenging to study such envenomations. We present the case of a 20 year-old man with confirmed exposure to the wolf spider who developed cutaneous erythema with ulceration following the bite. There was no evidence of skin necrosis. He was treated with aggressive wound care and systemic antibiotics for wound infection, with subsequent resolution of symptoms. This case adds to the limited knowledge regarding wolf spider envenomations and describes the clinical effects and management of wolf spider envenomation., (Copyright © 2012 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.)

Spiders are a source of intrigue and fear, and several myths exist about their medical effects. Many people believe that bites from various spider species cause necrotic ulceration, despite evidence that most suspected cases of necrotic arachnidism are caused by something other than a spider bite. Latrodectism and loxoscelism are the most important clinical syndromes resulting from spider bite. Latrodectism results from bites by widow spiders (Latrodectus spp) and causes local, regional, or generalised pain associated with non-specific symptoms and autonomic effects. Loxoscelism is caused by Loxosceles spp, and the cutaneous form manifests as pain and erythema that can develop into a necrotic ulcer. Systemic loxoscelism is characterised by intravascular haemolysis and renal failure on occasion. Other important spiders include the Australian funnel-web spider (Atrax spp and Hadronyche spp) and the armed spider (Phoneutria spp) from Brazil. Antivenoms are an important treatment for spider envenomation but have been less successful than have those for snake envenomation, with concerns about their effectiveness for both latrodectism and loxoscelism., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Previously reported cases of acute generalized exanthematous pustulosis secondary to brown recluse spider bite have been questioned due to lack of identification of the spider or because of the concomitant administration of antibiotics. We report a 9-year-old boy who arrived at the emergency department with a confirmed Loxosceles reclusa bite to the neck. On the third day of hospitalization, he developed hundreds of monomorphous, sterile pustules, initially in intertriginous areas. The eruption disseminated and was followed by pinpoint desquamation typical for acute generalized exanthematous pustulosis. During this he also developed late onset Coombs-positive hemolytic anemia and systemic loxoscelism. Sphingomyelinase in Loxosceles venom induces the production of interleukin-8 and granulocyte-macrophage colony-stimulating factor, cytokines involved in the pathogenesis of acute generalized exanthematous pustulosis, providing a mechanism by which Loxosceles reclusa bite may trigger acute generalized exanthematous pustulosis. We suggest that this case adds Loxosceles envenomation to the spectrum of agents that can trigger acute generalized exanthematous pustulosis., (© 2011 Wiley Periodicals, Inc.)

Spider bites are a worldwide problem. Brown recluse spider bites can lead to severe local or systemic clinical effects, such as edema, necrotic ulcer, rashes, fever, chills, nausea, vomiting, malaise, arthralgia, myalgia, hemolysis, leukocytosis, disseminated intravascular coagulation, renal failure, and death. Eyelid bites from brown recluse spiders are rare. We report a child with severe facial edema and a dermonecrotic ulcer on the eyelid. Upon laboratory examination, leukocytosis with a significant left shift was detected. The patient was treated with antibiotics, systemic corticosteroid and conservative therapy that included saline compresses and ocular lubrication. No surgical excision was required. Vision was not impaired. A dermonecrotic ulcer is a severe complication of brown recluse spider bites. Since the diagnosis is difficult, clinical and epidemiological findings and a detailed history are important for an accurate diagnosis.

Brown recluse spider (Loxosceles) bites cause lesions ranging from chronic necrotic ulcers to acute life-threatening sepsis. Based on our experience in treating acute and chronic wounds with negative pressure, we postulated that vacuum-assisted closure (VAC) would be valuable in this application. Chester pigs were procured and injected with purified brown recluse spider venom, 1 µl of venom in two anterior sites and 0·1 µl of venom in two posterior sites on their dorsum. For each concentration of venom, treatment consisted of either VAC or dry, non adherent dressings (control group). Each day, the wounds were inspected and measured. For wounds receiving 1·0 µl of venom, the control wounds decreased in surface area to 50% of initial size after 7 days and none had healed, whereas VAC-treated wounds were less than 50% after 48 hours and completely healed and reepithelialised after 8 days. Wounds with 0·1 µl of venom had 50% reduction after 5 days with no complete healing for control wounds, and the VAC wounds were 50% after 48 hours and all had closed and reepithelialised after 5 days. Our experimental study showed an accelerated healing time in the animals treated with the VAC as compared with controls., (© 2010 The Authors. Journal Compilation © 2010 Blackwell Publishing Ltd and Medicalhelplines.com Inc.)

The venom of Loxosceles spiders produces severe dermonecrotic damage, intravascular hemolysis, systemic alterations and risk of death. Clostridium perfringens is present in the microbial flora of the fangs and venom glands of Loxosceles intermedia. Its inoculation with the venom may infect the wound site and exacerbate the dermonecrotic damage. This anaerobic bacterium is widely distributed in nature and capable of damage with similar characteristics and severity to the spider venom. In this study we isolated and characterized species of Clostridium from the fangs and venom glands of Loxosceles laeta, including C. perfringens. The sensitivity patterns of different isolates of C. perfringens were evaluated by minimum inhibitory concentration against penicillin, ampicillin, erythromycin, gentamicin, chloramphenicol, clindamycin and tetracycline, under anaerobic conditions, using the method of microdilution in broth. Strain C. perfringens H28 showed resistance to penicillin, ampicillin, tetracycline and chloramphenicol. Resistance to penicillin and ampicillin was mediated by beta-lactamase. In vivo evaluation of dermonecrosis in rabbits using L. laeta venom co-inoculated with isolate C. perfringens H28 produced an increase in the area of dermonecrotic lesions in the presence of penicillin and tetracycline, but not with gentamicin. Antibiotic therapy Loxosceles poisoning should be re-evaluated, considering the existence of multi-resistant strains of C. perfringens., ((c) 2010. Published by Elsevier Ltd.)

Loxosceles reclusa (brown recluse spider) bites often cause local envenomation reactions; however, acute hemolysis from systemic loxoscelism is rare. To highlight this important diagnostic consideration for unexplained hemolysis in areas endemic for brown recluse spiders, we report on 6 adolescents with acute hemolytic anemia from presumed L reclusa bites.

Objectives: To verify the effect on erectile tissue of mice of two neuropeptides extracted from the poison of a spider, Phoneutria nigriventer, (Tx2-5 and -6, termed 'eretina') after direct injection into the corpus cavernosum, to assess the minimum dosage necessary for effect, the time for initiation of action, the local duration of the erection, histological effects and the presence of local and systemic side-effects., Materials and Methods: When applied intraperitoneally, eretina promotes the relaxation of cavernous smooth muscle, thus causing penile erection. Thirty-five mice were divided in two groups; 10 control mice were injected 20 microL of saline solution, and in the treated group, 25 mice were divided into groups of five and each subgroup received eretina in decreasing doses (0.024, 0.012, 0.006, 0.003 and 0.0015 microg/kg) until the minimum dose that produced an erection was determined. After treatment all mice were monitored to determine the response and any collateral effects., Results: The minimum dose producing an erection was 0.006 microg/kg, the five mice in this group having evidence of an erection at 35-45 min after injection. The histology of the cavernosum of mice treated with eretina showed dilatation and congestion of the vascular spaces with more blood than in controls. With the minimum dose there were no local or systemic collateral effects and the erection was lost after 120-140 min., Conclusion: The minimum dose of eretina producing an erection in mice was determined, and the agent was safe for this use as it did not produce any collateral toxic effects. These studies indicate a possible means of determining the mechanism of action of eretina.

The black widow spider (BWS), which is a member of the arthropod family, is widely distributed on earth. Black widow spider bites can cause a wide variety of signs or symptoms in humans, but the cardiovascular manifestations are relatively rare except hypertension/hypotension and bradycardia/tachycardia. We report on a 65-year-old man who experienced myocarditis after BWS envenomation, which is extremely rare. He complained of chest pain after the BWS bite, and electrocardiography (ECG) was consistent with a 0.5-mm ST-segment elevation in leads II, aVF, and V3 through V6 and accompanying augmentation in T-wave amplitude in leads V3 through V6 without reciprocal changes. Creatine kinase-MB, troponin-I, and aspartate aminotransferase levels peaked at 98 IU/L, 6.1 ng/mL, and 62 U/L, respectively. His ECG readings and cardiac enzymes returned to normal with supportive treatment, and he was discharged with complete recovery. To the best of our knowledge, the present case is the third in the literature reporting myocarditis and the first reporting ST-segment elevation and accompanying augmentation in T-wave amplitude after BWS envenomation. In addition to usual measures, we recommend ECG and cardiac-specific enzyme followup for every patient envenomated by BWS for potentially fatal cardiac involvement.

The incidence of scorpion stings and spider bites is high in Latin America. This is particularly true for Mexico, part of Amazonia, and southern and eastern Brazil. Centruroides and Tityus scorpion stings present a real danger for humans, especially children. Envenomation results in intense pain, neurological signs, and cardiorespiratory manifestations that can lead to death by acute pulmonary edema or heart failure. In the event of confirmed envenomation, antivenin must be administered as soon as possible in association with symptomatic treatment and, if necessary, cardiorespiratory resuscitation. Spider bites are a less frequent and severe. Envenomation by Loxosceles is extremely painful and necrotizing. Severe visceral complications can develop. An effective antivenim has recently become available for local and systemic envenomation. Envenomation by Latrodectus leads to neurological symptoms that can also be treated with antivenom. Envenomation by other spiders is less frequent and generally harmless.

Confirmed envenomations due to Loxosceles reclusa have not been previously documented in Turkey, to our knowledge. This brief report describes two Turkish patients with suspected envenomation by Loxosceles spider bites on the eyelids. Material obtained by swabbing the lesions with gauze was tested using a venom-specific enzyme-linked immunosorbent assay (ELISA). Both patients tested positive for the presence of Loxosceles venom.

Reports of spider bites appear throughout North America. Bites associated with the brown recluse spider (Loxosceles recluse) cause serious medical complications because the venom of this spider contains a powerful necrotising agent with the potential to cause severe cutaneous necrosis. Although not much is known regarding the application of negative pressure wound therapy (NPWT) to spider bites, this therapy has considerable literature support for its efficacy, cost-effectiveness and ease of use in chronic, difficult-to-heal wounds. A case study using NPWT to successfully treat a non healing upper arm wound presumed due to a venomous spider bite is presented here. The patient was successfully treated with a new, less costly NPWT product called the Versatile 1 and a new combination drain plus dressing called the Miller DermiVex drain, both manufactured by Blue Sky Medical (Carlsbad, CA).

An 11-year-old male presented with fever, rash, and a necrotic lesion on the lobule of the left ear. The lesion became tender and formed an eschar over 4 days. The patient developed leukocytosis, hemolytic anemia, and proteinuria, and was diagnosed with systemic loxoscelism from a brown recluse spider bite. He was managed with supportive therapy and improved in 4 days. Loxoscelism is a clinical diagnosis which should be suspected in an otherwise healthy patient with a necrotic wound, particulary in the endemic Southern and Midwestern United States. Physicians should be aware of this disease entity and its complications.

Objective: To compare the efficacy of intravenous versus intramuscular antivenom (AV) in the treatment of Red-back spider (RBS) envenoming., Methods: Randomized, double-dummy, double-blind, multicentre trial of patients with red-back spider envenoming requiring AV treatment recruited from five hospital EDs in Western Australia., Results: Thirty-five patients were recruited; two were excluded; 33 were available for initial analysis, but two who were unblinded after one ampoule of trial AV and given i.v. AV had limited data; 31 remained in the study and had more complete data. After AV, pain scores for both i.m. and i.v. groups improved rapidly. At 24 h, the i.v. group was better with a 55% absolute difference (76% vs. 21%; 95% CI 25-85% difference) in the proportion pain-free. There were no safety issues., Conclusions: Red-back spider antivenom was initially effective by both i.m. and i.v. routes. The study generates the hypothesis that at 24 h, significantly more patients are pain-free with i.v. administration. Definitive recommendations on the optimal route of administration of RBS AV await the results of further studies.

Brown recluse spiders (Loxosceles reclusa) are responsible for virtually all documented cases of spider bites leading to significant necrosis. The actual spider bite often goes unnoticed for as long as 4 to 6 hours, which makes diagnosis and, therefore, appropriate treatment, difficult. The spider bite generally results in either a necrotic wound or systemic symptoms that can lead to hemolysis. The patient described in this article experienced both complications. Dapsone and hyperbaric oxygen therapy brought the adverse response to the bite under control. The patient was hospitalized for 7 days during treatment for hemolysis and an extensive, necrotic wound. Efforts are underway to develop an assay to provide a definitive diagnosis for the brown recluse spider bite, but none is yet commercially available. Antivenom is scarce; capture of the offending spider appears to be most helpful in the diagnosis and proper treatment of spider bites.

LIMITED RISKS: Although most species of spiders are venomous, only ten or so are able to induce human envenomations. From a systematic point of view, it is possible to distinguish the araneomorph spiders - or "true" spiders - from the mygalomorph spiders. Dangerous species for humans can be found in both groups. Regarding "true' spiders, two kinds of envenomation are frequent, ubiquitous and potentially severe: latrodectism (neurotoxic symptomatology) due to the Widow spiders of the Latrodectus species,and loxoscelism (viscero-cutaneous symptomatology). Regarding the mygalomorph spiders, the Australian species responsible for atraxism (neurotoxic symptomatology) are considered as the most dangerous. Most of the other mygalomorph spiders, when they bite, only provoke benign loco regional problems. A supplementary defensive weapon exists in certain South-American species: urticating hairs which may induce severe ocular damage.

Objective: To dispel prevalent myths surrounding diagnosis of dermonecrotic and associated conditions supposedly resulting from bites of brown recluse, hobo, or other spiders in Canada., Sources of Information: Worldwide, spider bites are regularly misdiagnosed as the etiologic agents in human dermonecrosis mainly as a result of inaccurate, erroneous, or hyperbolic popular and professional literature based on inference, circumstantial evidence, inferior clinical trials, and misunderstanding of the facts regarding spider-bite envenomation., Main Message: A working diagnosis of "spider bite" or publishing a case history should be considered only when a spider is caught in the act of biting or otherwise reliably associated with a lesion. Accurate identification of the spider could be critical for correct diagnosis and subsequent treatment., Conclusion: Brown recluse spiders are not found in Canada. Hobo spiders have not been reliably implicated in dermonecrosis. Worldwide, spider-bite envenomation is an unlikely cause of dermonecrosis. Canadian physicians should give priority consideration to other, more likely, causes.

Twenty-five patients with definite bites by Badumna spp. spiders were recruited prospectively. Bites occurred across Australia, 92% from October to March, and most during daylight. Pain occurred in all cases, was severe in seven cases, with a median duration of 5 min. Other effects included: puncture marks (24%), swelling (12%) and erythema (68%). Minor systemic effects occurred in 4 bites. No patient had a necrotic ulcer (0%; 97.5% confidence interval 0-14%). Black house spiders (Badumna spp.) are unlikely to cause necrosis, contrary to reports of suspected bites. Patients can be reassured and do not require any further investigation or treatment.

Background: Redback spider bite is thought to be the commonest serious spider bite in Australia. The treatment for the envenomation syndrome it causes, termed 'latrodectism', is the most frequently used antivenom in Australia. Several cases of a 'latrodectism-like' illness after cupboard spider bites ('steatodism') have also appeared to respond to redback antivenom., Objective: This article describes the key presenting features of redback spider envenomation and discusses treatment for bites by this spider and that of its close relatives, the cupboard spider. It is intended that this information will assist general practitioners in the diagnosis and management of spider bite in Australia., Discussion: Redback spider antivenom is safe and appears to be broadly cross reactive with the venom of other spiders of the Theridiidae family. Guidelines for the use of this product are also provided.

Purpose: To report the effects to the eye following contact with spider contents., Design: Observational case report., Methods: A 46-year-old man presented with a painful and inflamed eye after contents of a spider got into his right eye when he squashed the spider with a newspaper. He suffered immediate severe pain in the eye, which rapidly became red and swollen. He had conjunctival edema and periorbital swelling of the eye and severe photophobia, but his vision was normal., Results: Topical local anesthetic was applied to the right eye, which was then flushed with normal saline for an hour. The redness and swelling began to resolve over 2 hours., Conclusions: Ocular exposure to the contents of a spider can cause severe pain, swelling, and redness associated with photophobia. The effects are short term, so reassurance, irrigation, and symptomatic treatment are sufficient.

The problem of dangerous dogs receives a lot of public attention. However, there is another group of animals that can threaten public security--the group of dangerous exotic animals. In daily routine mainly venomous snakes, spiders and scorpions or crocodiles, giant snakes and snapping turtles are of practical importance. The paper gives hints how to keep these animals according to animal protection and public safety rules.